I naturally get excited about many things biological, which inevitably leads to chasing multiple lines of research down the proverbial rabbit hole, and ultimately biting off way more than I can chew most of the time. There just aren't enough hours in the day to learn and share all that I want to with the world-wide web, while still managing to spend quality time with my family, attend to my teaching duties, and also squeeze in adequate sleep and perhaps a side of physical activity. I'm sure many out there can relate.
However, there is an emerging view in human health and disease that keeps popping up time and again (probably daily by my anecdotal observations) and I can't pass up the opportunity to share more on the blog about it. What is "it" you might ask? Drum roll, please... the human microbiome!
The
human microbiome is basically the collection of all the other microbial "critters" (bacteria, fungi, etc.) that are living on and in our bodies. In fact it is estimated that the number of microbial cells on and in our bodies
outnumber our own human cells ten to one!
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| One reason that microbes outnumber human cells is that bacteria are so much smaller than our cells! |
In many ways, our bodies can be thought of as ecosystems where many other species of microbial organisms are living in a delicate balance. The crazy thing is that since the discovery of microbes, the focus has been almost entirely on those few microbes that cause disease - aka - the pathogens. It can't be overstated that this view of the world has truly revolutionized humanity. We now understand the major culprits behind microbial killer diseases; we have learned to control many of them (for now!); and as a result, life-expectancy over the last century improved dramatically compared to human history prior to that point. Our own bias, including the scientists studying these things, means we tend to focus on those things which negatively impact us - e.g. a strep throat infection truly sucks, therefore we think bacteria are the enemy. But, times they are a changing... most people have heard of probiotics, right? One tangible result of this is all the major yogurt companies jumping on the "good" bacteria bandwagon. In reality, most of what is living on and in us are not pathogens under normal circumstances, and the harmless critters on and in us, may be just as important to our health as avoiding all the nasty pathogenic ones.
The thing is, we understand very little about these ecosystems on and within us. Enter, the
human microbiome project, a big project funded by the U.S. National Institutes of Health to characterize the communities on and within. What is normal? Are there different ecosystems associated with human disease (e.g. not just one pathogenic "bad" guy model)? The human microbiome project aims to answer these questions.
Just like ecosystems in the "macro" world (think of a forest), our own little ecosystems likely abide by the same rules. Growing up in rural Illinois, I distinctly remember a bit of a deer problem (Oh, deer!). Disrupt what was once a stable ecosystem by driving out the natural predators of deer, and with plenty of food available, those deer bred like rabbits! Is it possible we're breeding microbial "rabbits" in our own little ecosystems, and what would be the implications of that? The problem is, we don't understand our own ecosystems enough to answer those questions. It will be fascinating to see the data coming from the human microbiome project over the next few years!
Let's just say there is a lot of complexity going on here, and there is likely a link to allergy, so stay tuned for future posts! You'll truly be learning it with me because microbiology is definitely out of my human anatomy and physiology comfort zone!
Further reading:
Germs are us by Michael Specter in the New Yorker.
Excellent overview of the human microbiome, written in a very understandable way.
Red meat + wrong bacteria = bad news for hearts by Chris Woosten at Nature.
One of my interesting finds today, suggesting our microbes contribute to heart disease.
